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Liu N, Jiang T, Cui WP, Qi XQ, Li XG, Lu Y, Wu LF, Zhang WJ. The TorRS two component system regulates expression of TMAO reductase in response to high hydrostatic pressure in Vibrio fluvialis. Front Microbiol 2023; 14:1291578. [PMID: 38029070 PMCID: PMC10662104 DOI: 10.3389/fmicb.2023.1291578] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2023] [Accepted: 10/25/2023] [Indexed: 12/01/2023] Open
Abstract
High hydrostatic pressure (HHP) regulated gene expression is one of the most commonly adopted strategies for microbial adaptation to the deep-sea environments. Previously we showed that the HHP-inducible trimethylamine N-oxide (TMAO) reductase improves the pressure tolerance of deep-sea strain Vibrio fluvialis QY27. Here, we investigated the molecular mechanism of HHP-responsive regulation of TMAO reductase TorA. By constructing torR and torS deletion mutants, we demonstrated that the two-component regulator TorR and sensor TorS are responsible for the HHP-responsive regulation of torA. Unlike known HHP-responsive regulatory system, the abundance of torR and torS was not affected by HHP. Complementation of the ΔtorS mutant with TorS altered at conserved phosphorylation sites revealed that the three sites were indispensable for substrate-induced regulation, but only the histidine located in the alternative transmitter domain was involved in pressure-responsive regulation. Taken together, we demonstrated that the induction of TMAO reductase by HHP is mediated through the TorRS system and proposed a bifurcation of signal transduction in pressure-responsive regulation from the substrate-induction. This work provides novel knowledge of the pressure regulated gene expression and will promote the understanding of the microbial adaptation to the deep-sea HHP environment.
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Affiliation(s)
- Na Liu
- Laboratory of Deep-Sea Microbial Cell Biology, Institute of Deep-sea Science and Engineering, Chinese Academy of Sciences, Sanya, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Ting Jiang
- Laboratory of Deep-Sea Microbial Cell Biology, Institute of Deep-sea Science and Engineering, Chinese Academy of Sciences, Sanya, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Wen-Peng Cui
- Laboratory of Deep-Sea Microbial Cell Biology, Institute of Deep-sea Science and Engineering, Chinese Academy of Sciences, Sanya, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Xiao-Qing Qi
- Laboratory of Deep-Sea Microbial Cell Biology, Institute of Deep-sea Science and Engineering, Chinese Academy of Sciences, Sanya, China
- Institution of Deep-sea Life Sciences, IDSSE-BGI, Sanya, China
- International Associated Laboratory of Evolution and Development of Magnetotactic Multicellular Organisms, CAS, Sanya, China
| | - Xue-Gong Li
- Laboratory of Deep-Sea Microbial Cell Biology, Institute of Deep-sea Science and Engineering, Chinese Academy of Sciences, Sanya, China
- Institution of Deep-sea Life Sciences, IDSSE-BGI, Sanya, China
- International Associated Laboratory of Evolution and Development of Magnetotactic Multicellular Organisms, CAS, Sanya, China
| | - Yuan Lu
- College of Information Science & Engineering, Ocean University of China, Qingdao, China
| | - Long-Fei Wu
- International Associated Laboratory of Evolution and Development of Magnetotactic Multicellular Organisms, CAS, Sanya, China
- Aix Marseille University, CNRS, LCB, Marseille, France
| | - Wei-Jia Zhang
- Laboratory of Deep-Sea Microbial Cell Biology, Institute of Deep-sea Science and Engineering, Chinese Academy of Sciences, Sanya, China
- Institution of Deep-sea Life Sciences, IDSSE-BGI, Sanya, China
- International Associated Laboratory of Evolution and Development of Magnetotactic Multicellular Organisms, CAS, Sanya, China
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Maurel MC, Leclerc F, Hervé G. Ribozyme Chemistry: To Be or Not To Be under High Pressure. Chem Rev 2019; 120:4898-4918. [DOI: 10.1021/acs.chemrev.9b00457] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Marie-Christine Maurel
- Institut de Systématique, Evolution, Biodiversité (ISYEB), CNRS, Sorbonne Université, Muséum National d’Histoire Naturelle, EPHE, F-75005 Paris, France
| | - Fabrice Leclerc
- Institute for Integrative Biology of the Cell (I2BC), CNRS, CEA, Université Paris Sud, F-91198 Gif-sur-Yvette, France
| | - Guy Hervé
- Laboratoire BIOSIPE, Sorbonne Université, CNRS, Institut de Biologie Paris-Seine, Campus Pierre et Marie Curie, F-75005 Paris, France
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3
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Yin QJ, Zhang WJ, Qi XQ, Zhang SD, Jiang T, Li XG, Chen Y, Santini CL, Zhou H, Chou IM, Wu LF. High Hydrostatic Pressure Inducible Trimethylamine N-Oxide Reductase Improves the Pressure Tolerance of Piezosensitive Bacteria Vibrio fluvialis. Front Microbiol 2018; 8:2646. [PMID: 29375513 PMCID: PMC5767261 DOI: 10.3389/fmicb.2017.02646] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Accepted: 12/19/2017] [Indexed: 11/20/2022] Open
Abstract
High hydrostatic pressure (HHP) exerts severe effects on cellular processes including impaired cell division, abolished motility and affected enzymatic activities. Transcriptomic and proteomic analyses showed that bacteria switch the expression of genes involved in multiple energy metabolism pathways to cope with HHP. We sought evidence of a changing bacterial metabolism by supplying appropriate substrates that might have beneficial effects on the bacterial lifestyle at elevated pressure. We isolated a piezosensitive marine bacterium Vibrio fluvialis strain QY27 from the South China Sea. When trimethylamine N-oxide (TMAO) was used as an electron acceptor for energy metabolism, QY27 exhibited a piezophilic-like phenotype with an optimal growth at 30 MPa. Raman spectrometry and biochemistry analyses revealed that both the efficiency of the TMAO metabolism and the activity of the TMAO reductase increased under high pressure conditions. Among the two genes coding for TMAO reductase catalytic subunits, the expression level and enzymatic activity of TorA was up-regulated by elevated pressure. Furthermore, a genetic interference assay with the CRISPR-dCas9 system demonstrated that TorA is essential for underpinning the improved pressure tolerance of QY27. We extended the study to Vibrio fluvialis type strain ATCC33809 and observed the same phenotype of TMAO-metabolism improved the pressure tolerance. These results provide compelling evidence for the determinant role of metabolism in the adaption of bacteria to the deep-sea ecosystems with HHP.
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Affiliation(s)
- Qun-Jian Yin
- Laboratory of Deep-sea Microbial Cell Biology, Institute of Deep-sea Science and Engineering, Chinese Academy of Sciences, Sanya, China.,University of Chinese Academy of Sciences, Beijing, China.,International Associated Laboratory of Evolution and Development of Magnetotactic Multicellular Organisms, CNRS-Marseille/CAS, Beijing, China
| | - Wei-Jia Zhang
- Laboratory of Deep-sea Microbial Cell Biology, Institute of Deep-sea Science and Engineering, Chinese Academy of Sciences, Sanya, China.,International Associated Laboratory of Evolution and Development of Magnetotactic Multicellular Organisms, CNRS-Marseille/CAS, Beijing, China.,CAS Key Laboratory for Experimental Study under Deep-sea Extreme Conditions, Institute of Deep-sea Science and Engineering, Chinese Academy of Sciences, Sanya, China
| | - Xiao-Qing Qi
- Laboratory of Deep-sea Microbial Cell Biology, Institute of Deep-sea Science and Engineering, Chinese Academy of Sciences, Sanya, China.,International Associated Laboratory of Evolution and Development of Magnetotactic Multicellular Organisms, CNRS-Marseille/CAS, Beijing, China
| | - Sheng-Da Zhang
- Laboratory of Deep-sea Microbial Cell Biology, Institute of Deep-sea Science and Engineering, Chinese Academy of Sciences, Sanya, China
| | - Ting Jiang
- Laboratory of Deep-sea Microbial Cell Biology, Institute of Deep-sea Science and Engineering, Chinese Academy of Sciences, Sanya, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Xue-Gong Li
- Laboratory of Deep-sea Microbial Cell Biology, Institute of Deep-sea Science and Engineering, Chinese Academy of Sciences, Sanya, China.,International Associated Laboratory of Evolution and Development of Magnetotactic Multicellular Organisms, CNRS-Marseille/CAS, Beijing, China.,CAS Key Laboratory for Experimental Study under Deep-sea Extreme Conditions, Institute of Deep-sea Science and Engineering, Chinese Academy of Sciences, Sanya, China
| | - Ying Chen
- Laboratory for Experimental Study under Deep-sea Extreme Conditions, Institute of Deep-sea Science and Engineering, Chinese Academy of Sciences, Sanya, China
| | - Claire-Lise Santini
- International Associated Laboratory of Evolution and Development of Magnetotactic Multicellular Organisms, CNRS-Marseille/CAS, Beijing, China.,LCB UMR 7283, CNRS-Marseille, Aix-Marseille Université, Marseille, France
| | - Hao Zhou
- Engineering Laboratory of Engineering Department, Institute of Deep-sea Science and Engineering, Chinese Academy of Sciences, Sanya, China
| | - I-Ming Chou
- CAS Key Laboratory for Experimental Study under Deep-sea Extreme Conditions, Institute of Deep-sea Science and Engineering, Chinese Academy of Sciences, Sanya, China.,Laboratory for Experimental Study under Deep-sea Extreme Conditions, Institute of Deep-sea Science and Engineering, Chinese Academy of Sciences, Sanya, China
| | - Long-Fei Wu
- International Associated Laboratory of Evolution and Development of Magnetotactic Multicellular Organisms, CNRS-Marseille/CAS, Beijing, China.,LCB UMR 7283, CNRS-Marseille, Aix-Marseille Université, Marseille, France
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Kawano H, Suzaki Y, Fukuchi J, Nakasone K, Abe F, Kato C, Yoshida Y, Usami R, Horikoshi K. Cloning and Overproduction of therpoZGene Encoding an RNA Polymerase ω Subunit from a Deep-sea PiezophilicShewanella violaceaStrain DSS12. ACTA ACUST UNITED AC 2009; 15:118-22. [PMID: 15346766 DOI: 10.1080/1042517042000208626] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
We have cloned the rpoZ gene, encoding RNA polymerase omega protein, by PCR approach from the deep-sea piezophilic and psychrophilic bacterium, Shewanella violacea strain DSS12. The cloned gene, 285bp in length, was found to encode a protein consisting of 94 amino acid residues with a molecular mass of 10,327 Da. Significant homology was evident comparing the RpoZ protein of S. violacea with that of Shewanella oneidensis (69% identity), Vibrio cholerae (65% identity), Escherichia coli K-12 (64% identity) and Haemophilus influenzae (61% identity). From the Northern blot analysis, S. violacea rpoZ gene was expressed constitutively under pressure conditions of 0.1, 30 and 50MPa. We constructed expression plasmid to overproduce the RpoZ protein and transformed into E. coli JM109 as a host of overproduction. Upon induction, the recombinant protein encoded by plasmid pQrpoZ was overexpressed and purified using Ni2+ affinity column.
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Affiliation(s)
- Hiroaki Kawano
- The Deepstar Group, Japan Marine Science and Technology Center, 2-15 Natsushima-cho, Yokosuka, Kanagawa 237-0061, Japan.
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Kawano H, Abe F, Nakasone K, Kato C, Yoshida Y, Usami R, Horikoshi K. Cloning and characterization of the rpoE gene encoding an RNA polymerase sigmaE factor from the deep-sea piezophilic Shewanella violacea strain DSS12. ACTA ACUST UNITED AC 2005; 16:69-74. [PMID: 16040350 DOI: 10.1080/10425170400024482] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
The rpoE gene encoding an RNA polymerase sigmaE subunit was isolated from a gamma-phage library of the deep-sea piezophilic and psychrophilic bacterium Shewanella violacea strain DSS12. Structual analysis showed that the gene organization of the fragment containing S. violacearpoE was the l-aspartate oxidase-coding gene, rpoE, rseA, rseB and rseC in that order, the same as in the case of Photobacterium profundum SS9 and Escherichia coli K-12. The cloned gene, 576 bp in length, was found to encode a protein consisting of 192 amino acid residues with a molecular mass of 21,806 Da. Amino acid alignment of the RpoE protein showed that the functional domains responsible for DNA recognition, DNA melting, core binding, and RseA interaction were highly conserved. We purified hexahistidine-fused RpoE protein by constructing an overexpression plasmid. Core-binding analysis revealed that the cloned RpoE protein has the ability to bind with core RNA polymerase as a sigma factor.
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Affiliation(s)
- Hiroaki Kawano
- Extremobiosphere Research Center (XBR), Japan Agency for Marine-Earth Science and Technology (JAMSTEC), 2-15 Natsushima-cho, Yokosuka, Kanagawa, 237-0061, Japan.
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Li S, Xiao X, Li J, Luo J, Wang F. Identification of genes regulated by changing salinity in the deep-sea bacterium Shewanella sp. WP3 using RNA arbitrarily primed PCR. Extremophiles 2005; 10:97-104. [PMID: 16133656 DOI: 10.1007/s00792-005-0476-x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2005] [Accepted: 07/25/2005] [Indexed: 11/30/2022]
Abstract
The differential gene transcription of a deep-sea bacterium Shewanella sp. WP3 in response to changing salinity was analyzed by RNA fingerprinting using arbitrarily primed PCR (RAP-PCR). Ninety primer sets were used to scan two different RNA pools derived from cultures of 1% and 7% NaCl concentrations. Forty-three putative differential-expressed fragments were identified, cloned, and sequenced. Six out of the 43 fragments were confirmed to be truly differentially transcribed in terms of changing salinity. The deduced amino acid sequences of the six gene fragments showed highest identities (66-96%) with ribosomal protein L24, ATP binding protein, and chaperon protein HscA of Shewanella oneidensis MR-1 (Y6, Y9, and Y29); isocitrate lyase of Pseudomonas aeruginosa (Y15); peptidylprolyl cis-trans isomerase of Shewanella sp. SIB1 (Y21), glutamine synthetase of Shewanella violacea (Y25), respectively. Four genes (Y6, Y15, Y21, and Y25) were up regulated in 7% NaCl, while the other two (Y9 and Y29) contained more abundant transcripts in 1% NaCl. The data suggested that strategies involved in controlling protein synthesis, protein folding and/or trafficking, glutamate concentration, fatty acid metabolism, and substance transporting were used for salt adaptation in Shewanella sp. WP3. The expression patterns of the six genes in response to transient stress shocks including salt shock (3% NaCl shift to 12%), cold shock (15 degrees C shift to 0 degrees C), and high-hydrostatic pressure shock (0.1 MPa shift to 50 MPa) were further examined. Y29 encoding the putative HscA chaperon protein was indicated to be involved in adaptation of all the stresses tested.
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Affiliation(s)
- Shengkang Li
- College of Life Science, Zhongshan University, Guangzhou, People's Republic of China
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7
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Kawano H, Nakasone K, Matsumoto M, Yoshida Y, Usami R, Kato C, Abe F. Differential pressure resistance in the activity of RNA polymerase isolated from Shewanella violacea and Escherichia coli. Extremophiles 2004; 8:367-75. [PMID: 15241657 DOI: 10.1007/s00792-004-0397-0] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2004] [Accepted: 04/20/2004] [Indexed: 12/01/2022]
Abstract
RNA polymerase was purified from the piezophile Shewanella violacea DSS12, and the transcriptional activity after pressure treatment was compared with that of the mesophile Escherichia coli. Application of pressure at 100 MPa for 30 min reduced the E. coli RNA polymerase activity to 60% of the activity at atmospheric pressure, whereas the S. violacea RNA polymerase maintained full activity, indicating that the S. violacea RNA polymerase is more stable than its E. coli counterpart. This result was supported by the analysis of the strength of subunit interactions of the enzyme from both species, using a high-pressure electrophoresis apparatus, which showed that a pressure of 140 MPa caused dissociation of E. coli RNA polymerase but not that of S. violacea RNA polymerase. On the other hand, the core enzyme of S. violacea RNA polymerase, which lacked the sigma70 factor, was dissociated at 140 MPa. These results suggest that the sigma70 factor is required for stabilization of S. violacea RNA polymerase under high-pressure conditions. In this paper, we provide in vitro evidence for piezoadaptation at the transcriptional level, using purified RNA polymerase from cells of S. violacea and E. coli.
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Affiliation(s)
- Hiroaki Kawano
- The DEEPSTAR Group, Japan Agency for Marine-Earth Science and Technology (JAMSTEC), 2-15 Natsushima-cho, Yokosuka, Kanagawa 237-0061, Japan
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Kato C, Nogi Y. Correlation between phylogenetic structure and function: examples from deep-sea Shewanella. FEMS Microbiol Ecol 2001; 35:223-230. [PMID: 11311432 DOI: 10.1111/j.1574-6941.2001.tb00807.x] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
The genus Shewanella is one of the typical deep-sea bacterial genera. Two isolated deep-sea Shewanella species, Shewanella benthica and Shewanella violacea, were found to be able to grow better under high hydrostatic pressure conditions than at atmospheric pressure. These species are not only piezophilic (barophilic), but also psychrophilic. Many psychrophilic and psychrotolerant Shewanella species have been isolated and characterized from cold environments, such as seawater in Antarctica or the North Sea. Some of these cold-adapted Shewanella were shown to be piezotolerant, meaning that growth occurs in a high-pressure habitat. In this review, we propose that two major sub-genus branches of the genus Shewanella should be recognized taxonomically, one group characterized as high-pressure cold-adapted species that produce substantial amounts of eicosapentaenoic acid, and the other group characterized as mesophilic pressure-sensitive species.
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Affiliation(s)
- C Kato
- The DEEPSTAR Group, Japan Marine Science and Technology Center, 2-15 Natsushima-cho, 237-0061, Yokosuka, Japan
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9
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Nakasone K, Ikegami A, Fujii S, Kato C, Horikoshi K. Isolation and piezoresponse of the rpoA gene encoding the RNA polymerase alpha subunit from the deep-sea piezophilic bacterium Shewanella violacea. FEMS Microbiol Lett 2000; 193:261-8. [PMID: 11111034 DOI: 10.1111/j.1574-6968.2000.tb09434.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
The rpoA gene encoding the alpha subunit of RNA polymerase from the deep-sea piezophilic bacterium Shewanella violacea DSS12 was cloned and sequenced. The rpoA gene was found to encode a polypeptide consisting of 329 amino acids with a molecular mass of 36238 Da. S. violacea alpha protein was expressed in a ts Escherichia coli mutant, to confirm whether the rpoA gene is functional. It complemented this mutation, indicating a chimeric RNA polymerase is assembled at the non-permissive temperature. Recombinant alpha protein was overexpressed using an expression plasmid harboring the rpoA gene and purified to near homogeneity. Primer extension analysis revealed that two transcriptional initiation sites are recognized by sigma(70) RNA polymerase. It also indicated that pressure response (piezoresponse) in the alpha operon occurred at the transcriptional level, suggesting some positive regulators may interact with the transcriptional apparatus and regulate the expression of the operon at different pressure conditions.
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Affiliation(s)
- K Nakasone
- The DEEP STAR Group, Japan Marine Science and Technology Center, Yokosuka, Kanagawa, Japan.
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Ikegami A, Nakasone K, Kato C, Nakamura Y, Yoshikawa I, Usami R, Horikoshi K. Glutamine synthetase gene expression at elevated hydrostatic pressure in a deep-sea piezophilic Shewanella violacea. FEMS Microbiol Lett 2000; 192:91-5. [PMID: 11040434 DOI: 10.1111/j.1574-6968.2000.tb09364.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
A glutamine synthetase gene (glnA) was isolated from a deep-sea piezophilic bacterium, Shewanella violacea strain DSS12. A 7.5-kb SacI fragment containing the complete glnA gene was cloned and sequenced. The glnA gene was found to encode a protein consisting of 469 amino acid residues, showing 75.0% identity to the glutamine synthetase of Escherichia coli. Primer extension analyses revealed two transcription initiation sites in glnA and expression from each site was positively regulated by pressure. Putative promoters recognized by sigma(70) and sigma(54) were identified in the region upstream of glnA. An electrophoretic mobility shift assay demonstrated that S. violacea sigma(54) specifically binds to the promoter region of glnA, suggesting that sigma(54) may play an important role in pressure-regulated transcription in this piezophilic bacterium.
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Affiliation(s)
- A Ikegami
- The DEEPSTAR Group, Japan Marine Science and Technology Center, Yokosuka, Japan
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Ikegami A, Nakasone K, Fujita M, Fujii S, Kato C, Usami R, Horikoshi K. Cloning and characterization of the gene encoding RNA polymerase sigma factor sigma(54) of deep-sea piezophilic Shewanella violacea. BIOCHIMICA ET BIOPHYSICA ACTA 2000; 1491:315-20. [PMID: 10760597 DOI: 10.1016/s0167-4781(00)00035-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We have recently reported that a sigma(54)-like factor recognizes a DNA element, designated as region A, upstream of a pressure-regulated operon in piezophilic Shewanella violacea strain DSS12 (Nakasone et al., FEMS Microbiology Lett. 176 (1999) 351-356). In this study, we isolated and characterized the rpoN gene of this piezophilic bacterium. The rpoN gene was found to encode a putative protein consisting of 492 amino acid residues with a predicted molecular mass of 55359 Da. Significant homology was evident comparing the rpoN sequence of S. violacea with that of Escherichia coli (62.8% identity), Vibrio anguillarum (61.7% identity) and Pseudomonas putida (57.0% identity). The DNA-binding domain at the C-terminus of sigma(54) is well conserved in the case of the S. violacea rpoN gene product and the helix-turn-helix motif and the RpoN box are also present. In addition, the conserved glutamine-rich domain is present at the N-terminus. sigma(54) in S. violacea was expressed at a relatively constant level under various growth conditions as determined by both primer extension and Western blotting analyses. By means of a recombinant plasmid, a hexahistidine-tagged derivative of the sigma(54) from strain DSS12 was overexpressed in Escherichia coli and purified to near homogeneity. An electrophoretic mobility shift assay demonstrated that the purified sigma(54) protein specifically recognizes region A in the above-mentioned pressure-regulated operon.
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Affiliation(s)
- A Ikegami
- Department of Applied Chemistry, Faculty of Engineering, Toyo University, 2100 Kujirai, Kawagoe, Saitama, Japan
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Abstract
There has been a renewal of interest in the survival strategies employed by deep-sea, high-pressure-adapted (piezophilic) microorganisms as well as in the effects of high pressure on mesophilic, 1-atmosphere-pressure-adapted microorganisms. This is partly the result of a greater appreciation of the adaptations of microorganisms to life in extreme environments and partly the result of the development of new techniques for examining physiological and molecular processes as a function of pressure.
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Affiliation(s)
- F Abe
- DEEPSTAR Group, Japan Marine Science and Technology Center (JAMSTEC), 2-15 Natsushima-cho, Yokosuka 237-0061, Japan.
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